A. Field of the Invention
This application relates to the field of seals and prophylactics; and particularly to the field of seals for post-surgical devices such as ostomy devices, and prophylactic devices used in contact with animal tissue.
B. Description of the Prior Art
Materials used in contact with animal tissue require a unique combination of properties. Generally, they must be soft and flexible so as to readily conform to the shape of the tissue without irritation. Frequently, the materials must have a certain "feel" and provide strength and ready release (low tack) such as in the case of surgical gloves and other prophylactic devices. When used as seals, the materials must intimately engage the skin or tissue to prevent leakage of the materials being sealed. The numerous plastics, rubbers, and natural materials do not possess all the optimum properties for use in the many applications in contact with animal tissue, and consequently there is a continuing need for improved materials in these applications.
For example, surgical procedures (for example colostomy, circumostomy, cutaneous ureterostomy, and ileostomy) have been developed which create an opening in internal organs which opening extends through the patient's skin, generally in the form of a stubby protrusion or stoma. Various body material such as fecal material and urine must regularly pass through the stoma out of the body into the external environment. Post-surgical patients having such operations must therefore wear bags to contain these bodily excretions.
Because of the obnoxious nature of these bodily excretions, it is important that there be a good seal between the stoma and the bag worn by the patient. Numerous enterostomy appliances are available for holding a bag in sealing engagement with the body of a patient. A critical element of all these devices is the sealing device or material which contacts the living tissues such as the skin and stoma of the patient. Such sealing device must be comfortable, reliable, non-irritable, sanitary, and easily held in place for long periods of time. Of prime importance is that the sealing device must be liquid and gas tight, and odorproof.
The sealing device can take the form of a simple washer-type gasket as described in U.S. Pat. No. 3,980,084 or a more complicated molded part such as described in U.S. Pat. No. 3,964,485. In all cases, however, a difficult sealing problem is encountered because of the stretching of the skin during normal body motion and the requirement that the seal be non-irritating and convenient to apply and remove.
A common ostomy sealing material is a gelatinous mixture of Karaya gum or other natural gums and glycerol. This mixture is water soluble and is a nutrient which is capable of supporting bacterial growth. Additionally, Karaya gels have limited shelf life and harden after storage for extended periods under ambient conditions.
Synthetic materials such as soft plastics, rubber, adhesives, fabric pads, and even metals have been tried with various degrees of success. Some of these materials are hard and uncomfortable, others require excessive pressure to provide a tight joint, and some adhere to the skin and are difficult to remove.